// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
 * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
 *
 * This file contains the interrupt descriptor management code. Detailed
 * information is available in Documentation/core-api/genericirq.rst
 *
 */
#include <generated/deconfig.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/radix-tree.h>
#include <linux/bitmap.h>
#include <linux/irqdomain.h>
#include <linux/sysfs.h>

#include "internals.h"

///*
// * lockdep: we want to handle all irq_desc locks as a single lock-class:
// */
//static struct lock_class_key irq_desc_lock_class;

//#if defined(CONFIG_SMP)
//static int __init irq_affinity_setup(char *str)
//{
//	alloc_bootmem_cpumask_var(&irq_default_affinity);
//	cpulist_parse(str, irq_default_affinity);
//	/*
//	 * Set at least the boot cpu. We don't want to end up with
//	 * bugreports caused by random comandline masks
//	 */
//	cpumask_set_cpu(smp_processor_id(), irq_default_affinity);
//	return 1;
//}
//__setup("irqaffinity=", irq_affinity_setup);

//static void __init init_irq_default_affinity(void)
//{
//	if (!cpumask_available(irq_default_affinity))
//		zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT);
//	if (cpumask_empty(irq_default_affinity))
//		cpumask_setall(irq_default_affinity);
//}
//#else
//static void __init init_irq_default_affinity(void)
//{
//}
//#endif

//#ifdef CONFIG_SMP
//static int alloc_masks(struct irq_desc *desc, int node)
//{
//	if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
//				     GFP_KERNEL, node))
//		return -ENOMEM;

//#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
//	if (!zalloc_cpumask_var_node(&desc->irq_common_data.effective_affinity,
//				     GFP_KERNEL, node)) {
//		free_cpumask_var(desc->irq_common_data.affinity);
//		return -ENOMEM;
//	}
//#endif

//#ifdef CONFIG_GENERIC_PENDING_IRQ
//	if (!zalloc_cpumask_var_node(&desc->pending_mask, GFP_KERNEL, node)) {
//#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
//		free_cpumask_var(desc->irq_common_data.effective_affinity);
//#endif
//		free_cpumask_var(desc->irq_common_data.affinity);
//		return -ENOMEM;
//	}
//#endif
//	return 0;
//}

//static void desc_smp_init(struct irq_desc *desc, int node,
//			  const struct cpumask *affinity)
//{
//	if (!affinity)
//		affinity = irq_default_affinity;
//	cpumask_copy(desc->irq_common_data.affinity, affinity);

//#ifdef CONFIG_GENERIC_PENDING_IRQ
//	cpumask_clear(desc->pending_mask);
//#endif
//#ifdef CONFIG_NUMA
//	desc->irq_common_data.node = node;
//#endif
//}

//#else
//static inline int
//alloc_masks(struct irq_desc *desc, int node) { return 0; }
//static inline void
//desc_smp_init(struct irq_desc *desc, int node, const struct cpumask *affinity) { }
//#endif

//static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
//			      const struct cpumask *affinity, struct module *owner)
//{
//	int cpu;

//	desc->irq_common_data.handler_data = NULL;
//	desc->irq_common_data.msi_desc = NULL;

//	desc->irq_data.common = &desc->irq_common_data;
//	desc->irq_data.irq = irq;
//	desc->irq_data.chip = &no_irq_chip;
//	desc->irq_data.chip_data = NULL;
//	irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
//	irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
//	irqd_set(&desc->irq_data, IRQD_IRQ_MASKED);
//	desc->handle_irq = handle_bad_irq;
//	desc->depth = 1;
//	desc->irq_count = 0;
//	desc->irqs_unhandled = 0;
//	desc->tot_count = 0;
//	desc->name = NULL;
//	desc->owner = owner;
//	for_each_possible_cpu(cpu)
//		*per_cpu_ptr(desc->kstat_irqs, cpu) = 0;
//	desc_smp_init(desc, node, affinity);
//}

//int nr_irqs = NR_IRQS;
//EXPORT_SYMBOL_GPL(nr_irqs);

//static DEFINE_MUTEX(sparse_irq_lock);
//static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);

//#ifdef CONFIG_SPARSE_IRQ

//static void irq_kobj_release(struct kobject *kobj);

//#ifdef CONFIG_SYSFS
//static struct kobject *irq_kobj_base;

//#define IRQ_ATTR_RO(_name) \
//static struct kobj_attribute _name##_attr = __ATTR_RO(_name)

//static ssize_t per_cpu_count_show(struct kobject *kobj,
//				  struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	int cpu, irq = desc->irq_data.irq;
//	ssize_t ret = 0;
//	char *p = "";

//	for_each_possible_cpu(cpu) {
//		unsigned int c = kstat_irqs_cpu(irq, cpu);

//		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
//		p = ",";
//	}

//	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
//	return ret;
//}
//IRQ_ATTR_RO(per_cpu_count);

//static ssize_t chip_name_show(struct kobject *kobj,
//			      struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	ssize_t ret = 0;

//	raw_spin_lock_irq(&desc->lock);
//	if (desc->irq_data.chip && desc->irq_data.chip->name) {
//		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
//				desc->irq_data.chip->name);
//	}
//	raw_spin_unlock_irq(&desc->lock);

//	return ret;
//}
//IRQ_ATTR_RO(chip_name);

//static ssize_t hwirq_show(struct kobject *kobj,
//			  struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	ssize_t ret = 0;

//	raw_spin_lock_irq(&desc->lock);
//	if (desc->irq_data.domain)
//		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
//	raw_spin_unlock_irq(&desc->lock);

//	return ret;
//}
//IRQ_ATTR_RO(hwirq);

//static ssize_t type_show(struct kobject *kobj,
//			 struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	ssize_t ret = 0;

//	raw_spin_lock_irq(&desc->lock);
//	ret = sprintf(buf, "%s\n",
//		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
//	raw_spin_unlock_irq(&desc->lock);

//	return ret;

//}
//IRQ_ATTR_RO(type);

//static ssize_t wakeup_show(struct kobject *kobj,
//			   struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	ssize_t ret = 0;

//	raw_spin_lock_irq(&desc->lock);
//	ret = sprintf(buf, "%s\n",
//		      irqd_is_wakeup_set(&desc->irq_data) ? "enabled" : "disabled");
//	raw_spin_unlock_irq(&desc->lock);

//	return ret;

//}
//IRQ_ATTR_RO(wakeup);

//static ssize_t name_show(struct kobject *kobj,
//			 struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	ssize_t ret = 0;

//	raw_spin_lock_irq(&desc->lock);
//	if (desc->name)
//		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
//	raw_spin_unlock_irq(&desc->lock);

//	return ret;
//}
//IRQ_ATTR_RO(name);

//static ssize_t actions_show(struct kobject *kobj,
//			    struct kobj_attribute *attr, char *buf)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
//	struct irqaction *action;
//	ssize_t ret = 0;
//	char *p = "";

//	raw_spin_lock_irq(&desc->lock);
//	for (action = desc->action; action != NULL; action = action->next) {
//		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
//				 p, action->name);
//		p = ",";
//	}
//	raw_spin_unlock_irq(&desc->lock);

//	if (ret)
//		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");

//	return ret;
//}
//IRQ_ATTR_RO(actions);

//static struct attribute *irq_attrs[] = {
//	&per_cpu_count_attr.attr,
//	&chip_name_attr.attr,
//	&hwirq_attr.attr,
//	&type_attr.attr,
//	&wakeup_attr.attr,
//	&name_attr.attr,
//	&actions_attr.attr,
//	NULL
//};
//ATTRIBUTE_GROUPS(irq);

//static struct kobj_type irq_kobj_type = {
//	.release	= irq_kobj_release,
//	.sysfs_ops	= &kobj_sysfs_ops,
//	.default_groups = irq_groups,
//};

//static void irq_sysfs_add(int irq, struct irq_desc *desc)
//{
//	if (irq_kobj_base) {
//		/*
//		 * Continue even in case of failure as this is nothing
//		 * crucial.
//		 */
//		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
//			pr_warn("Failed to add kobject for irq %d\n", irq);
//	}
//}

//static void irq_sysfs_del(struct irq_desc *desc)
//{
//	/*
//	 * If irq_sysfs_init() has not yet been invoked (early boot), then
//	 * irq_kobj_base is NULL and the descriptor was never added.
//	 * kobject_del() complains about a object with no parent, so make
//	 * it conditional.
//	 */
//	if (irq_kobj_base)
//		kobject_del(&desc->kobj);
//}

//static int __init irq_sysfs_init(void)
//{
//	struct irq_desc *desc;
//	int irq;

//	/* Prevent concurrent irq alloc/free */
//	irq_lock_sparse();

//	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
//	if (!irq_kobj_base) {
//		irq_unlock_sparse();
//		return -ENOMEM;
//	}

//	/* Add the already allocated interrupts */
//	for_each_irq_desc(irq, desc)
//		irq_sysfs_add(irq, desc);
//	irq_unlock_sparse();

//	return 0;
//}
//postcore_initcall(irq_sysfs_init);

//#else /* !CONFIG_SYSFS */

//static struct kobj_type irq_kobj_type = {
//	.release	= irq_kobj_release,
//};

//static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
//static void irq_sysfs_del(struct irq_desc *desc) {}

//#endif /* CONFIG_SYSFS */

static RADIX_TREE(irq_desc_tree, GFP_KERNEL);

static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
{
	radix_tree_insert(&irq_desc_tree, irq, desc);
}

struct irq_desc *irq_to_desc(unsigned int irq)
{
	return radix_tree_lookup(&irq_desc_tree, irq);
}
EXPORT_SYMBOL(irq_to_desc);

static void delete_irq_desc(unsigned int irq)
{
	radix_tree_delete(&irq_desc_tree, irq);
}

//#ifdef CONFIG_SMP
//static void free_masks(struct irq_desc *desc)
//{
//#ifdef CONFIG_GENERIC_PENDING_IRQ
//	free_cpumask_var(desc->pending_mask);
//#endif
//	free_cpumask_var(desc->irq_common_data.affinity);
//#ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
//	free_cpumask_var(desc->irq_common_data.effective_affinity);
//#endif
//}
//#else
//static inline void free_masks(struct irq_desc *desc) { }
//#endif

//void irq_lock_sparse(void)
//{
//	mutex_lock(&sparse_irq_lock);
//}

//void irq_unlock_sparse(void)
//{
//	mutex_unlock(&sparse_irq_lock);
//}

//static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
//				   const struct cpumask *affinity,
//				   struct module *owner)
//{
//	struct irq_desc *desc;

//	desc = kzalloc_node(sizeof(*desc), GFP_KERNEL, node);
//	if (!desc)
//		return NULL;
//	/* allocate based on nr_cpu_ids */
//	desc->kstat_irqs = alloc_percpu(unsigned int);
//	if (!desc->kstat_irqs)
//		goto err_desc;

//	if (alloc_masks(desc, node))
//		goto err_kstat;

//	raw_spin_lock_init(&desc->lock);
//	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
//	mutex_init(&desc->request_mutex);
//	init_rcu_head(&desc->rcu);

//	desc_set_defaults(irq, desc, node, affinity, owner);
//	irqd_set(&desc->irq_data, flags);
//	kobject_init(&desc->kobj, &irq_kobj_type);

//	return desc;

//err_kstat:
//	free_percpu(desc->kstat_irqs);
//err_desc:
//	kfree(desc);
//	return NULL;
//}

//static void irq_kobj_release(struct kobject *kobj)
//{
//	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);

//	free_masks(desc);
//	free_percpu(desc->kstat_irqs);
//	kfree(desc);
//}

//static void delayed_free_desc(struct rcu_head *rhp)
//{
//	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);

//	kobject_put(&desc->kobj);
//}

//static void free_desc(unsigned int irq)
//{
//	struct irq_desc *desc = irq_to_desc(irq);

//	irq_remove_debugfs_entry(desc);
//	unregister_irq_proc(irq, desc);

//	/*
//	 * sparse_irq_lock protects also show_interrupts() and
//	 * kstat_irq_usr(). Once we deleted the descriptor from the
//	 * sparse tree we can free it. Access in proc will fail to
//	 * lookup the descriptor.
//	 *
//	 * The sysfs entry must be serialized against a concurrent
//	 * irq_sysfs_init() as well.
//	 */
//	irq_sysfs_del(desc);
//	delete_irq_desc(irq);

//	/*
//	 * We free the descriptor, masks and stat fields via RCU. That
//	 * allows demultiplex interrupts to do rcu based management of
//	 * the child interrupts.
//	 * This also allows us to use rcu in kstat_irqs_usr().
//	 */
//	call_rcu(&desc->rcu, delayed_free_desc);
//}

//static int alloc_descs(unsigned int start, unsigned int cnt, int node,
//		       const struct irq_affinity_desc *affinity,
//		       struct module *owner)
//{
//	struct irq_desc *desc;
//	int i;

//	/* Validate affinity mask(s) */
//	if (affinity) {
//		for (i = 0; i < cnt; i++) {
//			if (cpumask_empty(&affinity[i].mask))
//				return -EINVAL;
//		}
//	}

//	for (i = 0; i < cnt; i++) {
//		const struct cpumask *mask = NULL;
//		unsigned int flags = 0;

//		if (affinity) {
//			if (affinity->is_managed) {
//				flags = IRQD_AFFINITY_MANAGED |
//					IRQD_MANAGED_SHUTDOWN;
//			}
//			mask = &affinity->mask;
//			node = cpu_to_node(cpumask_first(mask));
//			affinity++;
//		}

//		desc = alloc_desc(start + i, node, flags, mask, owner);
//		if (!desc)
//			goto err;
//		irq_insert_desc(start + i, desc);
//		irq_sysfs_add(start + i, desc);
//		irq_add_debugfs_entry(start + i, desc);
//	}
//	bitmap_set(allocated_irqs, start, cnt);
//	return start;

//err:
//	for (i--; i >= 0; i--)
//		free_desc(start + i);
//	return -ENOMEM;
//}

//static int irq_expand_nr_irqs(unsigned int nr)
//{
//	if (nr > IRQ_BITMAP_BITS)
//		return -ENOMEM;
//	nr_irqs = nr;
//	return 0;
//}

//int __init early_irq_init(void)
//{
//	int i, initcnt, node = first_online_node;
//	struct irq_desc *desc;

//	init_irq_default_affinity();

//	/* Let arch update nr_irqs and return the nr of preallocated irqs */
//	initcnt = arch_probe_nr_irqs();
//	printk(KERN_INFO "NR_IRQS: %d, nr_irqs: %d, preallocated irqs: %d\n",
//	       NR_IRQS, nr_irqs, initcnt);

//	if (WARN_ON(nr_irqs > IRQ_BITMAP_BITS))
//		nr_irqs = IRQ_BITMAP_BITS;

//	if (WARN_ON(initcnt > IRQ_BITMAP_BITS))
//		initcnt = IRQ_BITMAP_BITS;

//	if (initcnt > nr_irqs)
//		nr_irqs = initcnt;

//	for (i = 0; i < initcnt; i++) {
//		desc = alloc_desc(i, node, 0, NULL, NULL);
//		set_bit(i, allocated_irqs);
//		irq_insert_desc(i, desc);
//	}
//	return arch_early_irq_init();
//}

//#else /* !CONFIG_SPARSE_IRQ */

//struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned_in_smp = {
//	[0 ... NR_IRQS-1] = {
//		.handle_irq	= handle_bad_irq,
//		.depth		= 1,
//		.lock		= __RAW_SPIN_LOCK_UNLOCKED(irq_desc->lock),
//	}
//};

//int __init early_irq_init(void)
//{
//	int count, i, node = first_online_node;
//	struct irq_desc *desc;

//	init_irq_default_affinity();

//	printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);

//	desc = irq_desc;
//	count = ARRAY_SIZE(irq_desc);

//	for (i = 0; i < count; i++) {
//		desc[i].kstat_irqs = alloc_percpu(unsigned int);
//		alloc_masks(&desc[i], node);
//		raw_spin_lock_init(&desc[i].lock);
//		lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
//		mutex_init(&desc[i].request_mutex);
//		desc_set_defaults(i, &desc[i], node, NULL, NULL);
//	}
//	return arch_early_irq_init();
//}

//struct irq_desc *irq_to_desc(unsigned int irq)
//{
//	return (irq < NR_IRQS) ? irq_desc + irq : NULL;
//}
//EXPORT_SYMBOL(irq_to_desc);

//static void free_desc(unsigned int irq)
//{
//	struct irq_desc *desc = irq_to_desc(irq);
//	unsigned long flags;

//	raw_spin_lock_irqsave(&desc->lock, flags);
//	desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
//	raw_spin_unlock_irqrestore(&desc->lock, flags);
//}

//static inline int alloc_descs(unsigned int start, unsigned int cnt, int node,
//			      const struct irq_affinity_desc *affinity,
//			      struct module *owner)
//{
//	u32 i;

//	for (i = 0; i < cnt; i++) {
//		struct irq_desc *desc = irq_to_desc(start + i);

//		desc->owner = owner;
//	}
//	bitmap_set(allocated_irqs, start, cnt);
//	return start;
//}

//static int irq_expand_nr_irqs(unsigned int nr)
//{
//	return -ENOMEM;
//}

//void irq_mark_irq(unsigned int irq)
//{
//	mutex_lock(&sparse_irq_lock);
//	bitmap_set(allocated_irqs, irq, 1);
//	mutex_unlock(&sparse_irq_lock);
//}

//#ifdef CONFIG_GENERIC_IRQ_LEGACY
//void irq_init_desc(unsigned int irq)
//{
//	free_desc(irq);
//}
//#endif

//#endif /* !CONFIG_SPARSE_IRQ */

///**
// * generic_handle_irq - Invoke the handler for a particular irq
// * @irq:	The irq number to handle
// *
// */
//int generic_handle_irq(unsigned int irq)
//{
//	struct irq_desc *desc = irq_to_desc(irq);
//	struct irq_data *data;

//	if (!desc)
//		return -EINVAL;

//	data = irq_desc_get_irq_data(desc);
//	if (WARN_ON_ONCE(!in_irq() && handle_enforce_irqctx(data)))
//		return -EPERM;

//	generic_handle_irq_desc(desc);
//	return 0;
//}
//EXPORT_SYMBOL_GPL(generic_handle_irq);

//#ifdef CONFIG_HANDLE_DOMAIN_IRQ
///**
// * __handle_domain_irq - Invoke the handler for a HW irq belonging to a domain
// * @domain:	The domain where to perform the lookup
// * @hwirq:	The HW irq number to convert to a logical one
// * @lookup:	Whether to perform the domain lookup or not
// * @regs:	Register file coming from the low-level handling code
// *
// * Returns:	0 on success, or -EINVAL if conversion has failed
// */
//int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
//			bool lookup, struct pt_regs *regs)
//{
//	struct pt_regs *old_regs = set_irq_regs(regs);
//	unsigned int irq = hwirq;
//	int ret = 0;

//	irq_enter();

//#ifdef CONFIG_IRQ_DOMAIN
//	if (lookup)
//		irq = irq_find_mapping(domain, hwirq);
//#endif

//	/*
//	 * Some hardware gives randomly wrong interrupts.  Rather
//	 * than crashing, do something sensible.
//	 */
//	if (unlikely(!irq || irq >= nr_irqs)) {
//		ack_bad_irq(irq);
//		ret = -EINVAL;
//	} else {
//		generic_handle_irq(irq);
//	}

//	irq_exit();
//	set_irq_regs(old_regs);
//	return ret;
//}

//#ifdef CONFIG_IRQ_DOMAIN
///**
// * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain
// * @domain:	The domain where to perform the lookup
// * @hwirq:	The HW irq number to convert to a logical one
// * @regs:	Register file coming from the low-level handling code
// *
// *		This function must be called from an NMI context.
// *
// * Returns:	0 on success, or -EINVAL if conversion has failed
// */
//int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
//		      struct pt_regs *regs)
//{
//	struct pt_regs *old_regs = set_irq_regs(regs);
//	unsigned int irq;
//	int ret = 0;

//	/*
//	 * NMI context needs to be setup earlier in order to deal with tracing.
//	 */
//	WARN_ON(!in_nmi());

//	irq = irq_find_mapping(domain, hwirq);

//	/*
//	 * ack_bad_irq is not NMI-safe, just report
//	 * an invalid interrupt.
//	 */
//	if (likely(irq))
//		generic_handle_irq(irq);
//	else
//		ret = -EINVAL;

//	set_irq_regs(old_regs);
//	return ret;
//}
//#endif
//#endif

///* Dynamic interrupt handling */

///**
// * irq_free_descs - free irq descriptors
// * @from:	Start of descriptor range
// * @cnt:	Number of consecutive irqs to free
// */
//void irq_free_descs(unsigned int from, unsigned int cnt)
//{
//	int i;

//	if (from >= nr_irqs || (from + cnt) > nr_irqs)
//		return;

//	mutex_lock(&sparse_irq_lock);
//	for (i = 0; i < cnt; i++)
//		free_desc(from + i);

//	bitmap_clear(allocated_irqs, from, cnt);
//	mutex_unlock(&sparse_irq_lock);
//}
//EXPORT_SYMBOL_GPL(irq_free_descs);

///**
// * __irq_alloc_descs - allocate and initialize a range of irq descriptors
// * @irq:	Allocate for specific irq number if irq >= 0
// * @from:	Start the search from this irq number
// * @cnt:	Number of consecutive irqs to allocate.
// * @node:	Preferred node on which the irq descriptor should be allocated
// * @owner:	Owning module (can be NULL)
// * @affinity:	Optional pointer to an affinity mask array of size @cnt which
// *		hints where the irq descriptors should be allocated and which
// *		default affinities to use
// *
// * Returns the first irq number or error code
// */
//int __ref
//__irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
//		  struct module *owner, const struct irq_affinity_desc *affinity)
//{
//	int start, ret;

//	if (!cnt)
//		return -EINVAL;

//	if (irq >= 0) {
//		if (from > irq)
//			return -EINVAL;
//		from = irq;
//	} else {
//		/*
//		 * For interrupts which are freely allocated the
//		 * architecture can force a lower bound to the @from
//		 * argument. x86 uses this to exclude the GSI space.
//		 */
//		from = arch_dynirq_lower_bound(from);
//	}

//	mutex_lock(&sparse_irq_lock);

//	start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
//					   from, cnt, 0);
//	ret = -EEXIST;
//	if (irq >=0 && start != irq)
//		goto unlock;

//	if (start + cnt > nr_irqs) {
//		ret = irq_expand_nr_irqs(start + cnt);
//		if (ret)
//			goto unlock;
//	}
//	ret = alloc_descs(start, cnt, node, affinity, owner);
//unlock:
//	mutex_unlock(&sparse_irq_lock);
//	return ret;
//}
//EXPORT_SYMBOL_GPL(__irq_alloc_descs);

//#ifdef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
///**
// * irq_alloc_hwirqs - Allocate an irq descriptor and initialize the hardware
// * @cnt:	number of interrupts to allocate
// * @node:	node on which to allocate
// *
// * Returns an interrupt number > 0 or 0, if the allocation fails.
// */
//unsigned int irq_alloc_hwirqs(int cnt, int node)
//{
//	int i, irq = __irq_alloc_descs(-1, 0, cnt, node, NULL, NULL);

//	if (irq < 0)
//		return 0;

//	for (i = irq; cnt > 0; i++, cnt--) {
//		if (arch_setup_hwirq(i, node))
//			goto err;
//		irq_clear_status_flags(i, _IRQ_NOREQUEST);
//	}
//	return irq;

//err:
//	for (i--; i >= irq; i--) {
//		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
//		arch_teardown_hwirq(i);
//	}
//	irq_free_descs(irq, cnt);
//	return 0;
//}
//EXPORT_SYMBOL_GPL(irq_alloc_hwirqs);

///**
// * irq_free_hwirqs - Free irq descriptor and cleanup the hardware
// * @from:	Free from irq number
// * @cnt:	number of interrupts to free
// *
// */
//void irq_free_hwirqs(unsigned int from, int cnt)
//{
//	int i, j;

//	for (i = from, j = cnt; j > 0; i++, j--) {
//		irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
//		arch_teardown_hwirq(i);
//	}
//	irq_free_descs(from, cnt);
//}
//EXPORT_SYMBOL_GPL(irq_free_hwirqs);
//#endif

///**
// * irq_get_next_irq - get next allocated irq number
// * @offset:	where to start the search
// *
// * Returns next irq number after offset or nr_irqs if none is found.
// */
//unsigned int irq_get_next_irq(unsigned int offset)
//{
//	return find_next_bit(allocated_irqs, nr_irqs, offset);
//}

//struct irq_desc *
//__irq_get_desc_lock(unsigned int irq, unsigned long *flags, bool bus,
//		    unsigned int check)
//{
//	struct irq_desc *desc = irq_to_desc(irq);

//	if (desc) {
//		if (check & _IRQ_DESC_CHECK) {
//			if ((check & _IRQ_DESC_PERCPU) &&
//			    !irq_settings_is_per_cpu_devid(desc))
//				return NULL;

//			if (!(check & _IRQ_DESC_PERCPU) &&
//			    irq_settings_is_per_cpu_devid(desc))
//				return NULL;
//		}

//		if (bus)
//			chip_bus_lock(desc);
//		raw_spin_lock_irqsave(&desc->lock, *flags);
//	}
//	return desc;
//}

//void __irq_put_desc_unlock(struct irq_desc *desc, unsigned long flags, bool bus)
//	__releases(&desc->lock)
//{
//	raw_spin_unlock_irqrestore(&desc->lock, flags);
//	if (bus)
//		chip_bus_sync_unlock(desc);
//}

//int irq_set_percpu_devid_partition(unsigned int irq,
//				   const struct cpumask *affinity)
//{
//	struct irq_desc *desc = irq_to_desc(irq);

//	if (!desc)
//		return -EINVAL;

//	if (desc->percpu_enabled)
//		return -EINVAL;

//	desc->percpu_enabled = kzalloc(sizeof(*desc->percpu_enabled), GFP_KERNEL);

//	if (!desc->percpu_enabled)
//		return -ENOMEM;

//	if (affinity)
//		desc->percpu_affinity = affinity;
//	else
//		desc->percpu_affinity = cpu_possible_mask;

//	irq_set_percpu_devid_flags(irq);
//	return 0;
//}

//int irq_set_percpu_devid(unsigned int irq)
//{
//	return irq_set_percpu_devid_partition(irq, NULL);
//}

//int irq_get_percpu_devid_partition(unsigned int irq, struct cpumask *affinity)
//{
//	struct irq_desc *desc = irq_to_desc(irq);

//	if (!desc || !desc->percpu_enabled)
//		return -EINVAL;

//	if (affinity)
//		cpumask_copy(affinity, desc->percpu_affinity);

//	return 0;
//}
//EXPORT_SYMBOL_GPL(irq_get_percpu_devid_partition);

//void kstat_incr_irq_this_cpu(unsigned int irq)
//{
//	kstat_incr_irqs_this_cpu(irq_to_desc(irq));
//}

///**
// * kstat_irqs_cpu - Get the statistics for an interrupt on a cpu
// * @irq:	The interrupt number
// * @cpu:	The cpu number
// *
// * Returns the sum of interrupt counts on @cpu since boot for
// * @irq. The caller must ensure that the interrupt is not removed
// * concurrently.
// */
//unsigned int kstat_irqs_cpu(unsigned int irq, int cpu)
//{
//	struct irq_desc *desc = irq_to_desc(irq);

//	return desc && desc->kstat_irqs ?
//			*per_cpu_ptr(desc->kstat_irqs, cpu) : 0;
//}

//static bool irq_is_nmi(struct irq_desc *desc)
//{
//	return desc->istate & IRQS_NMI;
//}

///**
// * kstat_irqs - Get the statistics for an interrupt
// * @irq:	The interrupt number
// *
// * Returns the sum of interrupt counts on all cpus since boot for
// * @irq. The caller must ensure that the interrupt is not removed
// * concurrently.
// */
//unsigned int kstat_irqs(unsigned int irq)
//{
//	struct irq_desc *desc = irq_to_desc(irq);
//	unsigned int sum = 0;
//	int cpu;

//	if (!desc || !desc->kstat_irqs)
//		return 0;
//	if (!irq_settings_is_per_cpu_devid(desc) &&
//	    !irq_settings_is_per_cpu(desc) &&
//	    !irq_is_nmi(desc))
//	    return desc->tot_count;

//	for_each_possible_cpu(cpu)
//		sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
//	return sum;
//}

///**
// * kstat_irqs_usr - Get the statistics for an interrupt
// * @irq:	The interrupt number
// *
// * Returns the sum of interrupt counts on all cpus since boot for @irq.
// * Contrary to kstat_irqs() this can be called from any context.
// * It uses rcu since a concurrent removal of an interrupt descriptor is
// * observing an rcu grace period before delayed_free_desc()/irq_kobj_release().
// */
//unsigned int kstat_irqs_usr(unsigned int irq)
//{
//	unsigned int sum;

//	rcu_read_lock();
//	sum = kstat_irqs(irq);
//	rcu_read_unlock();
//	return sum;
//}
